﻿namespace _扩展方法测试
{
    internal class Program
    {
        static void Main(string[] args)
        {
            string str = "Hello, World!";

            Console.WriteLine(str.IsNullOrEmpty()); // 调用扩展方法
        }
    }

    public static class StringExtensions
    {
        public static bool IsNullOrEmpty(this string input)
        {
            return string.IsNullOrEmpty(input);
        }
    }


}